IMPACT OF MOLE DRAINS AND N-FERTILIZER RATES ON SOME SOIL PROPERTIES AND SUGAR BEET PRODUCTION IN CLAY SOIL.

A field experiment was conducted during two winter seasons 2013/2014 and 2014/2015 at El-HamulDistrict, Kafr El-Shiek Governorate, Egypt, to study and evaluate the effect of mole drains (2 and 4 m spacing between the ploughed lines and 60 cm depth) and applied N-fertilizer rates (100 N, 115 N and 130 N % from the recommended) + 3 ton/fed. of gypsum before cultivation on improving some soil physio-chemical properties and sugar beet production in heavy clay salt affected soil. Data showed that: Application of mole drainsseem to be more effective in decreasing soil salinity and sodcity especially, in the top soil (0-60cm) and narrow spacing between the ploughed lines (2m). The reduction of soil salinity (0-60cm) were 21.11, 21.44, 17.04, 11.74, 11.17 and 10.95 % after the first season and 31.26, 31.37, 34.54, 12.34, 17.44 and 20.05% after the second season for treatment of 2m spacing + 100% N, 2m spacing + 115% N, 2m spacing + 130% N, 4m + 100% N, 4m spacing + 115% N, 4m spacing + 130% N, respectively than control. The corresponding values of ESP were 13.56, 13.90, 13.22, 4.56, 12.25 and 11.85% after the first season and 18.81, 18.75, 19.38, 10.57, 15.74 and 16.93% after the second season respectively.Mole drains and gypsum seemed to be more effective on increasing Ca++/TSS ratio in the topsoil up to 60cm. Mole drainsapplication was reduced bulk density and penetration resistance of the soil.Narrow spacing is superior to wider spacing in reducing bulk density and penetration resistance of the soil.Basic infiltration rates before treatments application was 0.61 cm/hr while, after application varied from 1.56 to 1.85 cm/hr. Narrow spacing is superior to wider spacing in increasing basic infiltration rate. While, no obvious different between bulk density, penetration resistanceand basic infiltration values under N-fertilizerrates treatments. All moles drains treatments caused to significant increase in root and sugar yields in both seasons compared to control treatments. Root yield significant increased than control by 5.65, 6.98, 7.38, 5.02, 6.71 and 7.37 ton/fed. In the first season and 4.87, 6.53, 6.67, 4.70, 6.14 and 6.73 ton/fed. in the second season. In the same time sugar yield increased than control by 0.94, 1.15, 1.17, 0.82, 1.09 and 1.16 ton/fed. In the first season while at the second season the increase were 0.80, 1.07, 1.09, 0.87 and 1.01 ton/fed. On the other side quality % recorded the highest value with control (81.48 and 81.22%) in both seasons compared to other mole drains applications which recorded the lowest ones. The lowest values of N-uptake (35.20 to 36.44 kg.fed-1) were found with control, and the highest ones (44.10 to 55.38 kgfed-1) were found with treatments in both seasons.The low values of impurities (K, Na andAlfa-amino –N) in sugar beet roots were found with treatments compared to the control.